A common technique that forgerers use in association with negotiable instruments such as bank checks, money orders, stock certificates, titles to personal property, etc., is to cut something from one part of a negotiable document and paste it on another part of that document, or another like document. For a professional forgerer, this technique can be very successful even with many types of conventional types of paper on which the negotiable instrument is printed, typically known as "security paper" or "safety paper". While some techniques are known to minimize this possibility, sometimes such techniques are visually unattractive, and "intrusive" and confusing on the final security document produced. Also the techniques for producing such documents may be complex.
According to the present invention a security paper, security document, and method of production thereof are provided which have a number of advantages. The security paper and security document according to the present invention are very difficult to utilize in forging by the cut and paste method because of the disposition of the particular security elements provided on the security paper/document. While greatly minimizing the possibility of successful cut and paste forgery, the security paper/document according to the invention is unobtrusive, and will not normally be recognized by the user of the security document/negotiable instrument without careful inspection. Further, the method according to the present invention is simple and easy to utilize, and is susceptible to a multitude of easily made variations.
According to one aspect of the present invention, a security paper is provided comprising the a plurality of parallel lines having a substantially uniform first spacing, irregularly interrupted by a plurality of stripes having a second spacing significantly greater than the first spacing. The term "paper" as used in the present specification and claims means typical cellulosic products, cloth products, and/or synthetic products which are typically used for printing, writing, or other imaging of indicia, particularly negotiable instruments. The term "irregularly" as used in the present specification and claims means non-periodically, such as intermittently or randomly.
The parallel lines on the security paper according to the present invention preferably are substantially straight. Also they are preferably of substantially uniform thickness. They may be provided by flexographic printing, utilizing flexo ink, such as the type which becomes invisible if bleach is applied. Also, it is preferred that alphanumeric indicia be provided within the stripes. The alphanumeric indicia may be oriented so that it is parallel to the parallel lines, either all extending in the same direction, or preferably some extending top to bottom while others extend bottom to top. For example the alphanumeric indicia may comprise the word "security", or can be the name of the company supplying the negotiable instrument (e.g. "X Bank Note Co."). Alternatively the alphanumeric indicia may be oriented so that it is perpendicular to the parallel lines.
The first spacing and thickness of the lines may vary widely. One particular example, however, is that the spacing and thickness of the lines is such that about eight lines are provided per centimeter, and the second spacing is typically at least twice as great as the first spacing, e.g. about 0.3 centimeters. For ease of production, e.g. by flexographic printing, the parallel lines interrupted by irregularly spaced stripes may be disposed in a pattern that repeats in an interval significantly greater than the length of the security document formed from the security paper, the interval and length not being evenly divisible. For example the pattern interval may be between about 15-17 inches (e.g. about 16.265 inches), while the length of the security document formed from the security paper is between about 5.5-12 inches (e.g. 11 inches), which would be common for the production of bank checks.
According to another aspect of the present invention a security document having first and second faces, a length, and a width is provided. At least one of the faces has a plurality of parallel lines having a substantially uniform first spacing, irregularly interrupted by a plurality of stripes having a second spacing significantly greater than the first spacing. At least one of the faces has readable alphanumeric indicia appropriate for a security document imaged thereon along the width or length. The parallel lines irregularly interrupted by stripes are disposed in a pattern that does not repeat within the length or width of the faces. The details of the security elements are as described above with respect to the security paper. The security document may be a bank check, money order, stock certificate, bond, car title, or any other type of conventional negotiable instrument.
A method of producing a security document is also provided according to the invention. The method comprises the steps of: (a) Flexographically printing at least a first face of a web of paper, in a relaxed state, with a plurality of substantially uniform thickness parallel lines having a substantially uniform first spacing, irregularly interrupted by a plurality of stripes having a second spacing significantly greater than the first spacing, and having a pattern repeating in a first interval. (b) Tensioning the web to stretch the pattern. (c) Imaging a face of the web with readable alphanumeric indicia appropriate for a security document repeating in a second interval, significantly less than the first interval. And, (d) cutting the web into individual security documents or sets of security documents.
There may be the further steps of taking up the web at a first location after step (b), and transporting it to another location for the practice of steps (c) and (d). Step (a) may be practiced only on the first face of the web and step (c) practiced on only the second face of the web, opposite the first face. Step (a) preferably is also further practiced to prim second alphanumeric indicia within the stripes. Step (c) may be practiced to image indicia for a bank check, and steps (a) through (d) are then typically practiced so that the first interval is between about 15-17 inches, and the second interval is between about 5.5-12 inches.
It is the primary object of the present invention to provide a simple security paper which is effective against cut and paste forgery, is non-intrusive, and despite the fact that it is simply produced, allows construction of security documents without a repeating pattern. This and other objects of the invention will become clear from an inspection of the detailed description of the invention and from the appended claims.